5.15-stable review patch. If anyone has any objections, please let me know.
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From: Christian König christian.koenig@amd.com
[ Upstream commit 2b95a7db6e0f75587bffddbb490399cbb87e4985 ]
Even the kerneldoc says that with a zero timeout the function should not wait for anything, but still return 1 to indicate that the fences are signaled now.
Unfortunately that isn't what was implemented, instead of only returning 1 we also waited for at least one jiffies.
Fix that by adjusting the handling to what the function is actually documented to do.
v2: improve code readability
Reported-by: Marek Olšák marek.olsak@amd.com Reported-by: Lucas Stach l.stach@pengutronix.de Signed-off-by: Christian König christian.koenig@amd.com Reviewed-by: Lucas Stach l.stach@pengutronix.de Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250129105841.1806-1-christian.koenig@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma-buf/dma-resv.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 8db368c7d35c3..cafaa54c3d9f1 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -619,11 +619,13 @@ long dma_resv_wait_timeout(struct dma_resv *obj, bool wait_all, bool intr, dma_resv_iter_begin(&cursor, obj, wait_all); dma_resv_for_each_fence_unlocked(&cursor, fence) {
- ret = dma_fence_wait_timeout(fence, intr, ret); - if (ret <= 0) { - dma_resv_iter_end(&cursor); - return ret; - } + ret = dma_fence_wait_timeout(fence, intr, timeout); + if (ret <= 0) + break; + + /* Even for zero timeout the return value is 1 */ + if (timeout) + timeout = ret; } dma_resv_iter_end(&cursor);